Preparation of phosphorus compounds

ABSTRACT

The present invention relates to a process for preparing phosphorus compounds and intermediates.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process for preparing phosphoruscompounds and intermediates.

2. Brief Description of the Prior Art

Deblon (Thesis No. 13920, ETH Zurich, 2000) and Maire (Thesis No. 14396,ETH Zurich, 2001) disclose that transition metal complexes ofolefin-phosphine compounds are particularly suitable for homogeneouscatalytic reactions, especially hydrogenations and hydrosilylations.Typically, they are prepared by using secondary phosphines (see alsoThomaier et al., New. J. Chem. 1998, 947–958 and Deblon et al., New. J.Chem. 2001, 25, 83–92), which is unsatisfactory for industrial use dueto their spontaneous combustibility and associated safety requirements.

There is therefore a need to develop a process for preparingolefin-phosphine compounds which does not require the use of secondaryphosphines.

SUMMARY OF THE INVENTION

Surprisingly, a process has now been found for preparing compounds ofthe formula (I)

in which

-   R¹ and R² are each independently a monovalent radical which in each    case has 1 to 30 carbon atoms or-   PR¹R² as a whole is a 5- to 9-membered heterocyclic radical which    contains a total of 2 to 50 carbon atoms and may contain up to three    further heteroatoms which are selected from the group of oxygen and    nitrogen, and-   A¹ and A² are each independently a substituted or unsubstituted    ortho-arylene radical and-   E is E¹ or E² where E¹ is an unsubstituted, monosubstituted or    disubstituted vicinal cis-alkenediyl radical and E² is a vicinal    alkanediyl radical in which the two yl carbon atoms each bear one or    two hydrogen atoms,    which is characterized in that    -   in a step a)        -   compounds of the formula (II)

-   -   -   in which A¹, A² and E are each as defined above are            converted by reacting with compounds of the formula (III)            R¹R²P-Hal  (III)        -   in which R¹ and R² are each as defined above and        -   Hal¹ is chlorine, bromine or iodine, preferably chlorine,        -   in the presence of acid or base,        -   to compounds of the formula (IV)

-   -   -   in which A¹, A², E, R¹ and R² are each as defined above and

    -   in a step b), the compounds of the formula (IV) are converted to        compounds of the formula (I) by reduction.

The compounds of formulae (I) and (IV) also encompass in particularchiral compounds. These may occur in various stereoisomeric forms whichbehave either as image and mirror image (enantiomers) or do not behaveas image and mirror image (diastereomers). The process according to theinvention is suitable both for the preparation of stereoisomericallypure forms of the particular compound or any mixtures of thestereoisomers, for example racemates or diastereomer pairs.

In the context of the invention, the terms stereoisomerically enriched(enantiomerically enriched or diastereomerically enriched) meanstereoisomerically pure (enantiomerically pure or diastereomericallypure) compounds or mixtures of stereoisomers (enantiomers ordiastereomers) in which one stereoisomer (enantiomer or diastereomer) ispresent in a greater fraction than another or the other.Stereoisomerically enriched means, for example and with preference, acontent of one stereoisomer of 50% to 100% by weight, more preferably70% to 100% by weight and most preferably 90 to 100% by weight, based onthe sum of the stereoisomers.

In one embodiment of the process according to the invention, in the caseof the presence of stereoisomer mixtures of compounds of the formula(IV), these may be separated in a manner known per se.

In the case of diastereomer mixtures, the separation may be effected,for example, by chromatography or by fractional crystallization, in thecase of enantiomer mixtures, for example, by fractional crystallizationin the presence of an enantiomerically enriched auxiliary reagent or bychromatography on an at least enantiomerically enriched column material.

In a further embodiment, the stability of the phosphorus-oxygen bond mayalso be used to convert at least one of the R¹, R², A¹, A² and Eradicals in the compounds of the formula (IV) by chemicaltransformations known per se to another R¹, R², A¹, A² and E radical.Chemical transformations known per se are, for example, customarytransformations of functional groups or functionalizations, as describedin J. March, Advanced Organic Chemistry, Wiley, 1992.

In the context of the invention, all radical definitions, parameters andillustrations hereinabove and listed hereinbelow, mentioned generally orwithin areas of preference, i.e. the particular areas and areas ofpreference, may be combined as desired.

DETAILED DESCRIPTION OF THE INVENTION

In the context of the invention, aryl as a substituent is, for example,carbocyclic aromatic radicals having 6 to 24 skeleton carbon atoms, forexample preferably phenyl, naphthyl, phenanthrenyl and anthracenyl, orheteroaromatic radicals having 5 to 24 skeleton carbon atoms in whichno, one, two or three skeleton carbon atoms per cycle, but at least oneskeleton carbon atom in the entire molecule, are substituted byheteroatoms which are selected from the group of nitrogen, sulphur andoxygen. They are, for example, preferably pyridinyl, oxazolyl,thiophenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl,dibenzothiophenyl, furanyl, indolyl, pyridazinyl, pyrazinyl, imidazolyl,pyrimidinyl and quinolinyl. In the context of the invention,specifications such as C₅ in the case of aryl radicals relates to thesum of the carbon atoms and heteroatoms of the aromatic skeleton.

Moreover, the carbocyclic aromatic radicals or heteroaromatic radicalsmay be substituted by up to five identical or different substituents percycle. For example and with preference, the substituents are selectedfrom the group of bromine, fluorine, chlorine, nitro, cyano, free andprotected formyl, free and protected hydroxyl, C₁–C₁₂-alkyl,C₁–C₁₂-haloalkyl, C₁–C₁₂-alkoxy, C₁–C₁₂-haloalkoxy, C₅–C₁₄-aryl, forexample phenyl, C₆–C₁₅-arylalkyl, for example benzyl,di(C₁–C₁₂-alkyl)amino, (C₁–C₁₂-alkyl)amino, CO(C₁–C₁₂-alkyl),OCO(C₁–C₁₂-alkyl), NHCO(C₁–C₁₂-alkyl), N(C₁–C₆-alkyl)CO(C₁–C₁₂-alkyl),CO(C₅–C₁₄-aryl), OCO(C₅–C₁₄-aryl), NHCO(C₅–C₁₄-aryl),N(C₁–C₆-alkyl)CO(C₅–C₁₄-aryl), COO—(C₁–C₁₂-alkyl), COO—(C₅–C₁₄-aryl),CON(C₁–C₁₂-alkyl)₂ or CONH(C₁–C₁₂-alkyl), CO₂M, CONH₂, SO₂NH₂,SO₂N(C₁–C₁₂-alkyl)₂, SO₃M where M is in each case optionally substitutedammonium, lithium, sodium, potassium or caesium.

For example and with preference, aryl is phenyl, naphthyl, pyridinyl andquinolinyl, each of which may be further substituted by no, one, two orthree radicals per cycle by radicals which are selected from the groupof fluorine, chlorine, cyano, C₁–C₈-alkyl, C₁–C₆-perfluoroalkyl,C₁–C₆-alkoxy, phenyl, benzyl, di(C₁–C₁₂-alkyl)amino, CO(C₁–C₁₂-alkyl),COO—(C₁–C₁₂-alkyl), CON(C₁–C₁₂-alkyl)₂ and SO₂N(C₁–C₁₂-alkyl)₂.

More preferably, aryl is phenyl or naphthyl, each of which may besubstituted by no, one, two or three radicals per cycle by radicalswhich are selected from the group of fluorine, chlorine, cyano,C₁–C₆-alkyl, C₁–C₆-perfluoroalkyl, C₁–C₈-alkoxy, phenyl andSO₂N(C₁–C₁₂-alkyl)₂.

In the context of the invention, the definition and the areas ofpreference also apply similarly to aryloxy substituents and the arylmoiety of an arylalkyl radical. Protected formyl means a formyl radicalwhich is protected by conversion to an aminal, acetal or a mixed aminalacetal, and aminals, acetals and mixed aminal acetals may be acyclic orcyclic.

For example and with preference, protected formyl is a1,1-(2,4-dioxycyclopentanediyl) radical.

Protected hydroxy is a hydroxyl radical which is protected by conversionto a ketal, acetal or a mixed aminal acetal, and the acetals and mixedaminal acetals may be acyclic or cyclic.

For example and with preference, protected hydroxyl is atetrahydropyranyl radical (THP).

In the context of the invention, alkyl, alkylene, alkoxy and alkenyl arein each case independently a straight-chain, cyclic, branched orunbranched alkyl, alkylene, alkenyl and alkoxy radical respectively,each of which may be further substituted by C₁–C₄-alkoxy in such a waythat each carbon atom of the alkyl, alkylene, alkoxy or alkenyl radicalbears at most one heteroatom selected from the group of oxygen, nitrogenand sulphur.

The same applies to the alkylene moiety of an arylalkyl radical.

In the context of the invention, C₁–C₆-alkyl is, for example, methyl,ethyl, 2-ethoxyethyl, n-propyl, isopropyl, n-butyl, tert-butyl,n-pentyl, cyclohexyl and n-hexyl, C₁–C₈-alkyl is additionally, forexample, n-heptyl, n-octyl or isooctyl, C₁–C₁₂-alkyl is furtheradditionally, for example, norbornyl, adamantyl, n-decyl and n-dodecyl,and C₁–C₁₈-alkyl is still further additionally n-hexadecyl andn-octadecyl.

In the context of the invention, C₁–C₄-alkylene is, for example,methylene, 1,1-ethylene, 1,2-ethylene, 1,1-propylene, 1,2-propylene,1,3-propylene, 1,1-butylene, 1,2-butylene, 2,3-butylene and1,4-butylene, and C₁–C₈-alkylene is additionally 1,5-pentylene,1,6-hexylene, 1,1-cyclohexylene, 1,4-cyclohexylene, 1,2-cyclohexyleneand 1,8-octylene.

In the context of the invention, C₁–C₄-alkoxy is, for example, methoxy,ethoxy, isopropoxy, n-propoxy, n-butoxy and tert-butoxy, andC₁–C₈-alkoxy is additionally cyclohexyloxy.

In the context of the invention, C₂–C₈-alkenyl is, for example, allyl,3-propenyl and 4-butenyl.

Haloalkyl and haloalkoxy are in each case independently astraight-chain, cyclic, branched or unbranched alkyl and alkoxy radicalrespectively, each of which is singly, multiply or fully substituted byhalogen atoms. Radicals which are fully substituted by fluorine arereferred to as perfluoroalkyl and perfluoroalkoxy respectively.

In the context of the invention, C₁–C₆-haloalkyl is, for example,trifluoromethyl, 2,2,2-trifluoroethyl, chloromethyl, fluoromethyl,bromomethyl, 2-bromoethyl, 2-chloroethyl, nonafluorobutyl.C₁–C₈-haloalkyl is additionally, for example, n-perfluorooctyl, andC₁–C₁₂-haloalkyl is additionally, for example, n-perfluorododecyl.

In the context of the invention, C₁–C₄-haloalkoxy is, for example,trifluoromethoxy, 2,2,2-trifluoroethoxy, 2-chloroethoxy,heptafluoroisopropoxy, and C₁–C₈-haloalkoxy is additionallyn-perfluorooctyloxy.

The preferred substitution patterns are defined hereinbelow:

-   R¹ and R² are preferably each independently C₁–C₁₈-alkyl,    C₃–C₁₂-alkenyl, C₁–C₁₈-perfluoroalkyl, C₁–C₁₈-perfluoroalkoxy,    C₁–C₁₈-alkoxy, C₅–C₂₄-aryl, C₅–C₂₄-aryloxy, C₅–C₂₅-arylalkyl,    C₅–C₂₅-arylalkoxy or NR⁴R⁵ where R⁴ and R⁵ are each independently    C₁–C₁₂-alkyl, C₅–C₁₄-aryl or C₆–C₁₅-arylalkyl, or NR⁴R⁵ as a whole    is a 5- to 7-membered cyclic amino radical having a total of 4 to 12    carbon atoms, or-   PR¹R² as a whole is a 5- to 7-membered heterocyclic radical of the    formula (V)

in which

-   Het¹ and Het² are each independently absent, or are each oxygen or    NR⁵ where R⁵ is C₁–C₁₂-alkyl, C₅–C₁₄-aryl or C₆–C₁₅-arylalkyl and-   K is an alkanediyl radical having 2 to 25 carbon atoms, a divalent    arylalkyl radical having 5 to 15 carbon atoms, an arylene radical    having a total of 5 to 14 carbon atoms or a 2,2′-(1,1′-bisarylene)    radical having a total of 10 to 30 carbon atoms.-   R¹ and R² are more preferably each independently C₁–C₁₂-alkyl,    C₅–C₁₄-aryl, C₆–C₂₅-arylalkyl or radicals of the formula (V) in    which Het¹ and Het² are each identically absent or are each    independently oxygen or nitrogen and-   K is a C₁–C₈-alkylene radical or a 2,2′-(1,1′-bisphenylene) or    2,2′-(1,1′-bisnaphthylene) radical which are further substituted by    up to two substituents per cycle selected from the group of    fluorine, chlorine, C₁–C₄-alkyl and C₁–C₄-alkoxy.-   R¹ and R² are even more preferably each independently and, still    more preferably, each identically, methyl, ethyl, n-propyl,    isopropyl, tert-butyl, cyclohexyl, benzyl, o-, m-, p-tolyl,    2,6-dimethylphenyl, 3,5-di-tert-butylphenyl,    p-trifluoromethylphenyl, 3,5-bis(trifluoromethylphenyl),    p-tert-butylphenyl, o-, m-, p-anisyl, 2,6-dimethoxyphenyl, o-, m-,    p-dimethylaminophenyl, 2-, 3-, 4-pyridyl, 2-furanyl, 2-pyrrolyl or    radicals of (IV) in which either    -   Het¹ and Het² are each absent and    -   K is a C₁–C₈-alkylene radical or    -   Het¹-K-Het² as a whole is a 2,2-dioxy-(1,1-binaphthyl) radical        or a 2,2′-dioxy-(1,1′-biphenyl) radical which is disubstituted        at least in the 6,6′-positions, but has at most two substituents        per cycle, and the substituents are selected from the group of        fluorine, chlorine, C₁–C₄-alkyl and C₁–C₄-alkoxy.-   PR¹R² is most preferably as a whole diisopropylphosphino,    di-tert-butylphosphino, dicyclohexylphosphino, diphenylphosphino,    bis(o-, m-, p-tolyl)phosphino,    di-(3,5-bis(trifluoromethylphenyl)phosphino, di-(o-anisyl)phosphino,    di-(2-pyridyl)phosphino, (R,R)-2,5-dimethylphospholano, or    (S,S)-2,5-dimethylphospholano.-   A¹ and A² are preferably each independently an ortho-phenylene    radical of the formula (VI)

in which

-   n is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and more preferably 0 or    1, and-   R⁶ is in each case independently selected from the group of    fluorine, chlorine, bromine, iodine, nitro, free and protected    formyl, C₁–C₁₂-alkyl, C₁–C₁₂-alkoxy, C₁–C₁₂-haloalkoxy,    C₁–C₁₂-haloalkyl, C₅–C₁₄-aryl, C₆–C₁₅-arylalkyl or radicals of the    formula (VII)    L-Q-T-W  (VII)    -   in which, each independently,    -   L is absent or is C₁–C₈-alkylene or C₂–C₈-alkenylene and    -   Q is absent or is oxygen, sulphur or NR⁷        -   where        -   R⁷ is hydrogen, C₁–C₈-alkyl, C₆–C₁₅-arylalkyl or C₅–C₁₄-aryl            and    -   T is a carbonyl group and    -   W is R⁸, OR⁸, NHR⁹ or N(R⁹)₂,        -   where        -   R⁸ is C₁–C₈-alkyl, C₅–C₁₅-arylalkyl or C₅–C₁₄-aryl and        -   R⁹ is in each case independently C₁–C₈-alkyl,            C₅–C₁₄-arylalkyl or C₄–C₁₅-aryl, or N(R⁹)₂ together is a 5-            or 6-membered cyclic amino radical,            or a radical of the formulae (VIIIa–g)            L-W  (VIIIa)            L-SO₂—W  (VIIIb)            L-NR¹²SO₂R¹²  (VIIIc)            L-SO₃Z  (VIIId)            L-PO₃Z₂  (VIIIe)            L-COZ  (VIIIf)            L-CN  (VIIIg)            in which L, Q, W and R⁸ are each as defined under the            formula (VII) and Z is hydrogen or M¹ where M¹ is as defined            under the definition of R⁷.-   A¹ and A² are more preferably each independently, even more    preferably identically, an ortho-phenylene radical of the    formula (VI) in which-   n is 0 or 1 and-   R⁶ is in each case independently selected from the group of    -   fluorine, chlorine, bromine, iodine, cyano, C₁–C₄-alkyl,        C₁–C₄-alkoxy, di-(C₁–C₄-alkyl)amino, (C₁–C₄-alkyl)amino,        C₁–C₄-alkylthio, CO₂M¹, CONH₂, SONH₂, SO₂N(C₁–C₄-alkyl)₂, SO₃M¹        where M¹ is in each case lithium, sodium or potassium.-   A¹ and A² are still more preferably identically an ortho-phenylene    radical of the formula (VI) in which-   n is 0 or 1 and-   R⁶ is selected from the group of fluorine, chlorine, cyano, methyl,    ethyl, methoxy, ethoxy, methylthio, dimethylamino, CONH₂,    SO₂N(methyl)₂ or SO₂N(ethyl)₂ where, when n=1, R⁶ is still more    preferably arranged in the para-position to E.-   A¹ and A² are most preferably each identically ortho-phenylene.-   E¹ is preferably a radical of the formula (IXa)

in which

-   R¹⁰ and R¹¹ are each independently hydrogen, cyano, fluorine,    chlorine, bromine, iodine, C₁–C₁₈-alkyl, C₄–C₂₄-aryl,    C₅–C₂₅-arylalkyl, CO₂M, CONH₂, SO₂N(R¹²)₂, SO₃M¹, where R¹² is in    each case independently as defined above or is a radical of the    formula (X),    T²-Het³-R¹³  (X)    -   in which    -   T² is absent or is carbonyl,    -   Het³ is oxygen or NR¹² where R¹² is hydrogen, C₁–C₁₂-alkyl,        C₅–C₁₄-aryl or C₆–C₁₅-arylalkyl and    -   R¹³ is C₁–C₁₈-alkyl, C₅–C₂₄-aryl or C₅–C₂₅-arylalkyl.-   E² is preferably a radical of the formula (IXb)

in which

-   R¹⁴ and R¹⁵ are each independently hydrogen, C₁–C₁₈-alkyl,    C₅–C₂₄-aryl or C₅–C₂₅-arylalkyl.-   E is preferably E¹.

E¹ is more preferably a radical of the formula (IXa) in which one of thetwo R¹⁰ and R¹¹ radicals is hydrogen and the other radical is selectedfrom the group of hydrogen, cyano, fluorine, C₁–C₁₂-alkyl, phenyl,C₁–C₁₈-alkoxy and C₅–C₁₅-arylalkoxy, where C₁–C₁₈-alkoxy andC₅–C₁₅-arylalkoxy are preferably chiral.

Very particular preference is given to one of the two R¹⁰ and R¹¹radicals being hydrogen and the other radical being selected from thegroup of hydrogen, cyano, fluorine, phenyl, methoxy and menthoxy,(−)-menthoxy being preferred among the 8 isomers.

The process according to the invention is especially suitable forpreparing the following compounds:

-   10-cyano-5-diphenylphosphinyl-5H-dibenzo[a,d]cycloheptene    (^(CN)tropp^(Ph)),-   5-(2S,5S-2,5-dimethylphospholanyl)-5H-dibenzo[a,d]cycloheptene    (S,S-tropphos^(Me)),-   5-(2R,5R-2,5-dimethylphospholanyl)-5H-dibenzo[a,d]cycloheptene    (R,R-tropphos^(Me)),-   (10-methoxy-5H-dibenzo[a,d]cyclohepten-5-yl)diphenylphosphine    (^(MeO)tropp^(Ph)),-   (10-methoxy-5H-dibenzo[a,d]cyclohepten-5-yl)dicyclohexylphosphine    (^(MeO)tropp^(Cyc)),-   [(5S)-10-[(−)-menthyloxy]-5H-dibenzo[a,d]cyclohepten-5-yl]diphenylphosphine,-   (S-^(menthyloxy)tropp^(Ph)) and    [(5R)-10-[(−)-menthyloxy]-5H-dibenzo[a,d]cyclohepten-5-yl]diphenylphosphine    (R-^(menthyloxy)tropp^(Ph)) are prepared.

In step a) of the process according to the invention, the compounds ofthe formula (II) are reacted with compounds of the formula (III) in thepresence of acid or base to give compounds of the formula (IV).

The reaction may optionally and preferably be carried out in thepresence of organic solvent, as long as the solvents are at leastsubstantially inert towards the particular acid or base used.

Suitable organic solvents are, for example:

aliphatic or aromatic, optionally halogenated hydrocarbons, for examplevarious benzines, benzene, toluene, xylene, chlorobenzene,dichlorobenzene, various petroleum ethers, hexane, cyclohexane,dichloromethane, chloroform, carbon tetrachloride; ethers such asdiethyl ether, methyl tert-butyl ether, diisopropyl ether, dioxane,tetrahydrofluan or ethylene glycol dimethyl ether or ethylene glycoldiethyl ether; amides such as N,N-dimethylformamide,N,N-dimethyl-acetamide, N-methylformanilide, N-methylpyrrolidone,N-methylcaprolactam or hexamethylphosphoramide; sulphoxides such asdimethyl sulphoxide, sulphones such as tetramethylenesulphone, alcoholssuch as methanol, ethanol, n- or isopropanol, ethylene glycol monomethylether, ethylene glycol monoethyl ether, diethylene glycol monomethylether, diethylene glycol monoethyl ether, or mixtures of such organicsolvents. Preferred organic solvents are ethers.

Suitable bases are, for example: alkaline earth metal or alkali metalhydrides, hydroxides, amides, alkoxides or carbonates, for examplesodium hydride, sodium amide, lithium diethylamide, sodium methoxide,sodium ethoxide, potassium tert-butoxide, sodium hydroxide, potassiumhydroxide, sodium carbonate and potassium carbonate, organolithiumcompounds, for example n-butyllithium or methyllithium, tertiary aminessuch as trimethylamine, triethylamine, tributylamine, trioctylamine,diisopropylethylamine, tetramethylguanidine, N,N-dimethylaniline,diazabicyclooctane (DABCO), diazabicyclononene (DBN) ordiazabicycloundecene (DBU), piperidine and N-methylpiperidine andN-heteroaromatics, for example pyridine and N,N-dimethylaminopyridine.

Preferred bases are tertiary amines in which the radicals are eachindependently selected from the group of C₁–C₁₂-alkyl, for exampletrimethylamine, triethylamine, tributylamine and trioctylamine, and evengreater preference is given to those tertiary amines which are liquidunder the selected reaction conditions.

Preference is given to using acids for the process according to theinvention.

Preferred acids are those which, based on an aqueous reference scale and25° C., have a pKa value of 5.5 or less.

These are, for example, (C₁–C₁₂-alkyl)carboxylic acids,(C₁–C₁₂-haloalkyl)carboxylic acids, (C₁–C₁₂-haloalkyl)sulphonic acids,(C₁–C₁₂-alkyl)sulphonic acids, (C₅–C₁₄-aryl)sulphonic acids, hydrogenchloride, hydrogen bromide and hydrogen iodide, optionally dissolved inacetic acid, sulphuric acid, ortho- and polyphosphoric acids,hexafluorophosphoric acid and tetrafluoroboric acid.

Particular preference is given to (C₁–C₁₂-haloalkyl)carboxylic acids, inparticular trifluoroacetic acid.

The reaction in step a) may be carried out, for example, at atemperature of −20° C. to 100° C., preferably at 0 to 80° C. and morepreferably at ambient temperature.

The reaction pressure may be, for example, 0.5 to 100 bar, preferably0.9 to 5 bar. Particular preference is given to ambient temperature.

For example and with preference, acid and compound of the formula (II)may be initially charged in an organic solvent and the compound of theformula (III) added.

In step b) of the process according to the invention, compounds of theformula (IV) are reduced.

Preference is given to effecting this reduction in the presence ofhydrosilicon compounds. Preferred hydrosilicon compounds arepolymethylhydrosiloxane (PHMS) or those of the formula (XI)(R¹⁶)_(p)SiH_(4-p)  (XI)in which

-   p is 0, 1, 2 or 3 and-   R¹⁶ is in each case independently C₁–C₈-alkyl, C₁–C₈-alkoxy,    C₅–C₁₄-aryl or chlorine, and even greater preference is given to    trichlorosilane.

Preference is given to carrying out the reaction in the presence ofsolvent. Preferred solvents are aliphatic or aromatic, optionallyhalogenated hydrocarbons, for example various benzines, benzene,toluene, xylene, chlorobenzene, dichlorobenzene, various petroleumethers, hexane, cyclohexane, dichloromethane, chloroform, carbontetrachloride or mixtures thereof.

The reaction in step b) may be carried out, for example, at atemperature of 20° C. to 200° C., preferably 50 to 150° C. and morepreferably at 100 to 150° C.

The reaction pressure may be, for example, 0.5 to 100 bar, preferably0.9 to 5 bar. Particular preference is given to ambient pressure.

For example and with preference, the hydrosilicon compound and thecompound of the formula (IV) may be initially charged at roomtemperature in an organic solvent and the reaction mixture then heatedat ambient pressure to the boiling point of the solvent used.

In a further aspect, the invention relates to compounds of the formula(IVa) and also to a process for preparing compounds of the formula (IVa)

-   in which A¹, A² and E are each as defined under the formula (I)    including their areas of preference and-   Hal is in each case independently chlorine, bromine or iodine,    preferably identically chlorine or bromine and more preferably    identically chlorine,    which is characterized in that compounds of the formula (II) as    defined above are reacted in the presence of acid or base with    compounds of the formula (IIIa)    PHal₃  (IIIa)    in which-   Hal is in each case independently chlorine, bromine or iodine,    preferably identically chlorine or bromine and more preferably    identically chlorine.

All specifications made above for step a) apply here correspondingly.

Compounds of the formula (IVa) include:

-   5-dichlorooxyphosphoryl-5H-dibenzo[a,d]cycloheptene (troppo^(Cl))    and 5-dibromooxyphosphoryl-5H-dibenzo[a,d]cycloheptene (troppo^(Br))

The compounds of the formula (IVa) are valuable intermediates and can beprepared, for example, by reacting with compounds of the formula (XII)R^(1/2)-M  (XII)in which R¹ and R² are each as defined above including the areas ofpreference specified and M, in the case that

-   R¹ or R² are to be bonded to the phosphorus atom via an oxygen atom,    is hydrogen or 1/n equivalent of a metal or of a metal fragment    having the valency n, and, in the case that-   R¹ or R² are to be bonded to the phosphorus atom via a nitrogen    atom, is hydrogen, and, in the case that-   R¹ or R² are to be bonded to the phosphorus atom via a carbon atom,    is 1/n equivalent of a metal or of a metal fragment having the    valency n, the same also applying in a similar manner to radicals in    which R¹R² as a whole is a divalent radical.

Preferred metals are alkali metal, alkaline earth metal or transitionmetals, for example lithium, potassium, sodium, magnesium, zinc orcopper, and particular preference is given to lithium, magnesium andzinc:

Preferred metal fragments are monovalent halometal fragments, forexample MgCl, MgBr, MgI, ZnCl, ZnBr and ZnI.

The compounds obtainable in this way which can be encompassed by theformula (IV) may then likewise be reduced in step b) to the freephosphines of the formula (I).

The compounds of the formula (I) which can be prepared in accordancewith the invention are especially suitable as ligands for metals and foruse in catalytic processes. Preferred catalytic processes arehydrogenations and hydrosilylations.

The compounds of the formula (IV) and (IVa) which can be prepared inaccordance with the invention are especially suitable for use in aprocess for preparing ligands and catalysts.

The advantage of the present invention is that, using compounds whichare easy to obtain and can be handled without risk, olefin-phosphoruscompounds can be prepared in high yields.

The invention is further illustrated but is not intended to be limitedby the following examples in which all parts and percentages are byweight unless otherwise specified.

EXAMPLES Example 1 Synthesis of5-diphenyloxophosphoranyldibenzo[a,d]cycloheptene (troppo^(ph))

In a 500 ml reaction vessel, 14 g of dibenzo[a,d]cyclohepten-5-ol (0.067mol) are dissolved in 250 ml of THF. Subsequently, 11.1 ml oftrifluoroacetic acid (0.144 mol) are added and subsequently 25.84 ml ofdichlorophenylphosphine (0.144 mol) are added. A white precipitateforms. The reaction mixture is left to stir at room temperature for 30minutes. Subsequently, the reaction mixture is neutralized using K₂CO₃solution. The organic phase is removed, and the residues are washedthree times with 100 ml of [lacuna] and once with 100 ml of Et₂O. Thecombined organic phases are dried over Na₂SO₄ and the solvent issubsequently removed. The residue is recrystallized from CH₂Cl₂/n-hexaneand 18.38 g (70% yield) of a colourless crystalline solid are obtained.

³¹P NMR (CDCl₃, 121 MHz): δ 29.28

¹H NMR (CDCl₃, 300 MHz): δ 4.93 [d, ²J(PH)=16 Hz, 1H, PCH_(benzyl)),6.56 (s, 2H, H_(olefin)), 7.59–7.17 (m, 19H, H_(arom)).

Example 2 Synthesis of 5-diphenylphosphinyldibenzo[a,d]cycloheptene(tropp^(ph))

In a 100 ml reaction vessel with reflux condenser, 1 g of troppo^(Ph)from Example 1 (2.7 mmol) is dissolved in 50 ml of toluene and admixedwith 2.6 ml of HSiCl₃. The reaction mixture is heated to 120° C. for 8h. The progress of the reaction is monitored by ³¹P NMR spectroscopy.The reaction mixture is cooled to 0° C. and 30 ml of a deoxygenated 20%NaOH solution are added dropwise. Subsequently, the organic phase isseparated and dried over Na₂SO₄. After the solvent has been evaporatedoff under reduced pressure, 0.88 g (93% yield) of pure tropp^(Ph) isobtained.

³¹P NMR (CDCl₃, 101 MHz): δ −14.2 (s).

¹H NMR (CDCl₃, 250 MHz): δ 4.93 (d, ²J(PH)=5.5 Hz, 2H, PCH_(benzyl)),7.20–6.87 (m, 15H, H_(arom)), 7.25 (s, 2H, H_(olefin)), 7.44–7.41 (m,3H, H_(arom))

Example 3 Synthesis of5-diphenyloxophosphoranyl-10-phenyldibenzo[a,d]cycloheptene(^(ph)troppo^(ph))

520 mg of 5-hydroxy-10-phenyldibenzo[a,d]cycloheptene (1.8 mmol) in 15ml of CH₂Cl₂ are admixed with 0.15 ml of CF₃COOH (1.13 mmol). Thesolution becomes red and 0.33 ml of chlorodiphenylphosphine (2.26 mmol)is added. Another 0.15 ml of CF₃COOH (1.13 mmol) is then added to thereaction mixture. This gives a clear yellow solution which is stirred atroom temperature for 2 h. Subsequently, 20 ml of Na₂CO₃ (18% in H₂O) areadded. The organic phase is removed and the aqueous extracted 3× with 20ml of CH₂Cl₂ each time. The combined organic phases are dried over MgSO₄and the solvent is subsequently evaporated. This gives a white foamwhich contains spectroscopically pure product (660 mg, 80%).

³¹P NMR: 27.3 ppm—¹H NMR: 5.15 (d, ²JPH=13 Hz, 1 H, CHP), 6.50 (s, 1 H,═CH), 7.0–7.9 (m, 23 H, H_(arom)).

Example 4 Synthesis of5-diphenylphosphinyl-10-phenyldibenzo[a,d]cycloheptene (^(ph)tropp^(ph))

660 mg of 5-diphenyloxophosphoranyl-10-phenyldibenzo[a,d]cycloheptene(1.44 mmol) are dissolved in 20 ml of toluene and 1.8 ml of SiHCl₃ areadded. The reaction mixture is heated to 120° C. under reflux for 10 h.After cooling, 25 ml of 20% deoxygenated KOH are added with cooling. Theorganic phase is removed and dried over MgSO₄. After removing allvolatile components, a yellow foam is obtained which fluorescesintensely under UV light.

³¹P NMR (CDCl₃): −13.1 ppm—¹H NMR: 4.99 (d, ²J_(PH)=6 Hz, 1H, CHP), 6.90(d, J_(PH)=6 Hz, 1 H, ═CH), 7.0–7.53 (m, 23 H, Harom).

Example 5 Synthesis of 5-diallyloxophosphoranyldibenzo[a,d]cycloheptene(troppo^(allyl))

To a solution of 50 mg of5-dichlorooxophosphoranyldibenzo[a,d]cycloheptene, which has beenprepared in a similar manner to Example 1 (0.2 mmol) in 1 ml of THF isadded 0.2 ml of allylmagnesium chloride (2 M in THF). The reactionmixture becomes red-brown. After 1 h at room temperature, the reactionmixture is admixed with aqueous ammonium chloride solution and theorganic phase is removed. The aqueous phase is extracted with CH₂Cl₂ andthe combined organic phases are dried over MgSO₄. After removing thesolvent, 5-diallyloxophosphoranyldibenzo[a,d]cycloheptene is obtained asa colourless solid.

³¹P NMR (CDCl₃): 45.8 ppm—¹H NMR: 2.44 (dd, ²J_(PH)=14.5 Hz, ³J_(HH)=7.6Hz, 2 H, CH₂), 4.49 (d, ²J_(PH)=16.2 Hz, 1 H, CHP).

Example 6 Synthesis of 5-diallylphosphinyldibenzo[a,d]cycloheptene(tropp^(allyl))

In a similar manner to Example 4,5-diallyloxophosphoranyldibenzo[a,d]cycloheptene is reducedquantitatively using HSiCl₃ in toluene within 2 h to5-diallylphosphinyldibenzo[a,d]cycloheptene.

³¹P NMR (CDCl₃): −28.1 ppm.

Although the invention has been described in detail in the foregoing forthe purpose of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art without departing from the spirit and scope of theinvention except as it may be limited by the claims

1. Process for preparing compounds of the formula (I)

in which R¹ and R² are each independently a monovalent radical which ineach case has 1 to 30 carbon atoms or PR¹R² as a whole is a 5- to9-membered heterocyclic radical which contains a total of 2 to 50 carbonatoms and optionally contains up to three further heteroatoms which areselected from the group of oxygen and nitrogen, and A¹ and A² are eachindependently a substituted or unsubstituted ortho-arylene radical and Eis E¹ or E² where E¹ is an unsubstituted, monosubstituted ordisubstituted vicinal cis-alkenediyl radical and E² is a vicinalalkanediyl radical in which the two yl carbon atoms each bear one or twohydrogen atoms, comprising in a step a), reacting compounds of theformula (II)

in which A¹, A² and E are each as defined above with compounds of theformula (III)R¹R²P-Hal  (III) in which R¹ and R² are each as defined above and Hal¹is chlorine, bromine or iodine, in the presence of acid or base, to formcompounds of the formula (IV)

in which A¹, A², E, R¹ and R² are each as defined above and in a stepb), reducing the compounds of the formula (IV) to compounds of theformula (I).
 2. Process according to claim 1, characterized in that R¹and R² are each independently C₁–C₁₈-alkyl, C₃–C₁₂-alkenyl,C₁–C₁₈-perfluoroalkyl, C₁–C₁₈-perfluoroalkoxy, C₁–C₁₈-alkoxy,C₅–C₂₄-aryl, C₅–C₂₄-aryloxy, C₅–C₂₅-arylalkyl, C₅–C₂₅-arylalkoxy orNR⁴R⁵ where R⁴ and R⁵ are each independently C₁–C₁₂-alkyl, C₅–C₁₄-arylor C₆–C₁₅-arylalkyl, or NR⁴R⁵ as a whole is a 5- to 7-membered cyclicamino radical having a total of 4 to 12 carbon atoms, or PR¹R² as awhole is a 5- to 7-membered heterocyclic radical of the formula (V)

in which Het¹ and Het² are each independently absent, or are each oxygenor NR⁵ where R⁵ is C₁–C₁₂-alkyl, C₅–C₁₄-aryl or C₆–C₁₅-arylalkyl and Kis an alkanediyl radical having 2 to 25 carbon atoms, a divalentarylalkyl radical having 5 to 15 carbon atoms, an arylene radical havinga total of 5 to 14 carbon atoms or a 2,2′-(1,1′-bisarylene) radicalhaving a total of 10 to 30 carbon atoms.
 3. Process according to claim1, characterized in that A¹ and A² are each independently anortho-phenylene radical of the formula (VI)

in which n is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and R⁶ is in eachcase independently selected from the group of fluorine, chlorine,bromine, iodine, nitro, free and protected formyl, C₁–C₁₂-alkyl,C₁–C₁₂-alkoxy, C₁–C₁₂-haloalkoxy, C₁–C₁₂-haloalkyl, C₅–C₁₄-aryl,C₆–C₁₅-arylalkyl or radicals of the formula (VII)L-Q-T-W  (VII) in which, each independently, L is absent or isC₁–C₈-alkylene or C₂–C₈-alkenylene and Q is absent or is oxygen, sulphuror NR⁷ where R⁷ is hydrogen, C₁–C₈-alkyl, C₆–C₁₅-arylalkyl orC₅–C₁₄-aryl and T is a carbonyl-group and W is R⁸, OR⁸, NHR⁹ or N(R⁹)₂,where R⁸ is C₁–C₈-alkyl, C₅–C₁₅-arylalkyl or C₅–C₁₄-aryl and R⁹ is ineach case independently C₁–C₈-alkyl, C₅–C₁₄-arylalkyl or C₄–C₁₅-aryl, orN(R⁹)₂ together is a 5- or 6-membered cycloamino radical, or a radicalof the formulae (VIIIa–g)L-W  (VIIIa)L-SO₂-W  (VIIIb)L-NR¹²SO₂R¹²  (VIIIc)L-SO₃Z  (VIIId)L-PO₃Z₂  (VIIIe)L-COZ  (VIIIf)L-CN  (VIIIg) in which L, Q, W and R⁸ are each as defined under theformula (VII) and Z is hydrogen or M¹ where M¹ is as defined under thedefinition of R⁷.
 4. Process according to claim 1, characterized in thatE is a radical of the formulae (IXa) or (IXb) where, in formula (IXa)

R¹⁰ and R¹¹ are each independently hydrogen, cyano, fluorine, chlorine,bromine, iodine, C₁–C₁₈-alkyl, C₄–C₂₄-aryl, C₅–C₂₅-arylalkyl, CO₂M,CONH₂, SO₂N(R¹²)₂, SO₃M¹, where R¹² is in each case independently asdefined above or is a radical of the formula (X),T²-Het³-R¹³  (X) in which T² is absent or is carbonyl, Het³ is oxygen orNR¹² where R¹² is hydrogen, C₁–C₁₂-alkyl, C₅–C₁₄-aryl orC₆–C₁₅-arylalkyl and R¹³ is C₁–C₁₈-alkyl, C₅–C₂₄-aryl orC₅–C₂₅-arylalkyl, and, in formula (IXb),

R¹⁴ and R¹⁵ are each independently hydrogen, C₁–C₁₈-alkyl, C₅–C₂₄-arylor C₅–C₂₅-arylalkyl.
 5. Process according to at least one of claims 1 to4, characterized in that10-cyano-5-diphenylphosphinyl-5H-dibenzo[a,d]cycloheptene(^(CN)tropp^(Ph))5-(2S,5S-2,5-dimethylphospholanyl)-5H-dibenzo[a,d]cycloheptene(S,S-tropphos^(Me))5-(2R,5R-2,5-dimethylphospholanyl)-5H-dibenzo[a,d]cycloheptene(R,R-tropphos^(Me))(10-methoxy-5H-dibenzo[a,d]cyclohepten-5-yl)diphenylphosphine(^(MeO)tropp^(Ph))(10-methoxy-5H-dibenzo[a,d]cyclohepten-5-yl)dicyclohexylphosphine(^(MeO)tropp^(Cyc))[(5S)-10-[(−)-menthyloxy]-5H-dibenzo[a,d]cyclohepten-5-yl]diphenylphosphine,(S-^(menthyloxy)tropp^(Ph)) and[(5R)-10-[(−)-menthyloxy]-5H-dibenzo[a,d]cyclohepten-5-yl]-diphenylphosphine(R-^(menthyloxy)tropp^(Ph)) are prepared.
 6. Process according to claim1, characterized in that acids are used for step a).
 7. Processaccording to claim 1, characterized in that the acids used are thosewhich, based on an aqueous reference scale and 25° C., have a pKa valueof 5.5 or less.
 8. Process according to claim 1, characterized in thatstep a) is carried out at a temperature of −20° C. to 100° C.
 9. Processaccording to claim 1, characterized in that stereoisomer mixtures ofcompounds of the formula (IV), are separated before carrying out stepb).
 10. Process according to at least one of claims 1 to 9,characterized in that at least one of the R¹, R², A¹, A² and E radicalsin the compounds of the formula (IV) is converted to another R¹, R², A¹,A² and E radical.
 11. Process according to claim 1, characterized inthat the reduction in step b) is carried out in the presence ofhydrosilicon compounds.
 12. Process according to claim 1, characterizedin that the reduction in step b) is carried out at a temperature of 20°C. to 200° C.
 13. Process according to claim 1, characterized in thatthe resulting compounds are reduced to the free phosphines in a furtherstep.
 14. Compounds of the formula (IVa)

in which A¹, A² and E are each as defined in claim
 1. 15.5-Dichlorooxyphosphoryl-5H-dibenzo[a,d]cycloheptene (troppo^(Cl)) and5-dibromooxyphosphoryl-5H-dibenzo[a,d]cycloheptene (troppo^(Br)). 16.Process for preparing compounds of the formula (IVa)

in which A¹, A² and E are each as defined in claim 1 and Hal is in eachcase chlorine, bromine or iodine, comprising reacting compounds of theformula (II) as defined in claim 1 in the presence of acid or base withcompounds of the formula (IIIa)PHal₃  (IIIa) in which Hal is in each case independently chlorine,bromine or iodine.
 17. Process according to claim 16, characterized inthat the compounds of the formula (IVa) are also reacted with compoundsof the formula (XII)R^(1/2)-M  (XII) in which R¹ and R² are each as defined in claim 1, andM, in the case that R¹ or R² are to be bonded to the phosphorus atom viaan oxygen atom, is hydrogen or 1/n equivalent of a metal or of a metalfragment having the valency n, and, in the case that R¹ or R² are to bebonded to the phosphorus atom via a nitrogen atom, is hydrogen, and, inthe case that R¹ or R² are to be bonded to the phosphorus atom via acarbon atom, is 1/n equivalent of a metal or of a metal fragment havingthe valency n, the same also applying in a similar manner to radicals inwhich R¹R² as a whole is a divalent radical.
 18. Process according toclaim 17, characterized in that the resulting compounds are reduced tothe free phosphines in a further step.
 19. A process for preparingligand for metals or conducting catalytic processes comprising providingthe compounds of claim
 14. 20. The process of claim 19, characterized inthat the catalytic processes are hydrogenations and hydrosilylations.